Improvement in progressive kilns



ZSheets--Shee F. E'. H oFFMANN.- Progressve-Klns.

Patented Dec. 22, 1874.

/l I lm ll/ '/l Wi THE GRAPHIC COAFHDTLTK3V9814IPARK PLACENY.

2SheetsSheet2. F. E. HOFFMANN. Progressive-Knus.

N0. 158,085. Patented Dec. 22,1874.

IIb/1151i ZW FREDERICK E. HOFFMANN, OF BERLIN, GERMANY.

IMPROVEMENT IN PROGRESSIVE KILNS.

Specification forming part of Letters Patent No. 158,0Q5, dated December 22, 1874; application filed December 9, 1874.

To all whom it may concern:

Be it known that I, FREDERICK E. HOFF- MANN, of Berlin, in the Kingdom of Prussia, in the Empire of Germany, have invented a certain new and useful Improvement in Progressive Kilns, of which the following is a specification This invention is illustrated in the accompanying drawing, in which Figure l represents a transverse vertical section in the plane w x, Fig. 2. Fig. 2 is a horizontal section in the plane y y, Fig. 1. Figs. 3 and 4 are de tails, which will be referred to as the description progresses.

Similar letters indicate corresponding parts.

This invention relates to a certain improvement on that class of progressive kilns which I have described in my Patents No. 48,244, dated June 13, 1865, and No. 115,734, dated June 6, 1871. 4

My present improvement consists in a hotair iiue, situated beneath the heating-chamber, and communicating with the same through apertures in the floors of the doorways, said doorways being separated from the heatingchamber by temporary partition-walls, which are provided with apertures, either above or below, so that the heat which escapes from the top of the heated compartment or compartments of the heating-chamber can be conducted to the lower part of the compartment or compartments containing fresh or green material, and thereby the waste heat is economized, and the fresh or green material is uniformly dried before it is exposed to the action of the fire.

In the example represented by the drawing, a circular kiln is shown, but my invention is applicable to progressive kilns of any suitable form.

In this drawing, the letter A designates the heating-chamber, the roof of which is provided with twelve, (more or less,) apertures, for the reception of a movable partition, c, by means of which the heating-chamber can be stopped up and formed into a number of sections, (1, 2, 3-l2,) corresponding to the number of apertures. Each of these sections is provided with a doorway, B, and with a smoketlue, D, and each of these fines is provided with a damper, and if the damper of one of these tlues is raised, the corresponding section of the heating-chamber is brought in communication with the chimney or smoke-stack. Near the licor of the kiln, about between the foundations of the double external wall thereof, is situated the hot-air iue C, which is made in the form of an annular channel, and which communicates with the interior of the kiln in a peculiar manner, as will be presently explained. It may be desirable to place this hotair flue in a different positionfor instance, entirely outside the kiln, beneath the surface of the ground, or beneath the heating-chamber Aitself. rIlhe hot-air lue communicates with the sections of the kiln through apertures o o, which are made in the bottom of each doorway, and lead down into the hot-air flue. These apertures are usually closed by a cast-iron cover, d, (see Fig. 3,) whose downwardly-projecting rim is embedded in a layer of sand, so as to produce an air-tight joint. Besides this, the apertures o are covered up by means of boards or planks b, so that the carts or wheelbarrows used for introducing or removing the article to be dried in the kiln can be driven in or out without coming in contact with the covers d. If the kiln is in operation the doorways of those sections which are lled with bricks, or other material to be dried, are closed by temporary walls u built up of bricks. If the aperture o, of the hot-air flue C in one of the doorways, is opened by removing the plank b and cover d, and if the temporary wall in this doorway is removed partially or wholly, and the exterior opening of said doorway is closed by a door, t, placed against the oblique outside wall, and luted with clay, the .air can circulate from the heating-ch amber into the hot-air iue, or vice versa. The door t is made of sheet metal, or of wood covered with sheet metal.

In that section of the kiln from which hot air is to be taken a portion of the top part of the temporary wall u is removed, and in that section which is filled with green bricks or fresh material the bottom part of the temporary brick wall is provided with one or more apertures.

The operation of the hot-air ue is as follows: I assume the kiln to be in full operation, and the fire to be burning in the secrFIon.

tions 9 and 10, while the heated gases escaping from these sections pass through sections 11, 12, and 1, and escape through the smokeiiue of this last-named section into the chimney. Between the sections 1 and 2 is a movable partition, a. Section 2 is filled with green bricks, and a second movable partition is introduced between sections 2 and 3, thus inclosing section 2 between two partitions. Green bricks are being introduced into section -3 5 from section 4 burned brick are carted out,

and sections 5, 6, and 7 contain bricks in the process ot' cooling. The surplus heated air from sections 5 and 6 is to be transferred to section 2, containing greenbricks. To effect this purpose the doorway of section 2 is walled up, and in the temporary wall one or more apertures are left close down to the bottom of the kiln, and the opening leading to the hotair flue in the doorway ot' this section is opened; the doorway of said section is closed on the outside by the door t, (see Fig. 2.) The upper part of the temporary wall in section 6 is then removed, the opening leading to the hot-air in the doorway of this section is opened, and the doorway is closed by the door t. All other openings of the hot-air iiue are closed; also all the smoke-fines, with the eX- ception of that of section 1, as previously stated. It the smoke-fine ot section 2 is also 5 and 6.

rent of heated air is produced through the section 2, and the moisture contained in the green material in this section is rapidly evaporated, and carried off through the smokestack.

It is desirable to place into the hot-air ue dampers 7c, (see Fig. 4,) and to open all those on the short arc between sections 6 and 2, the dampers on the long arc being closed.

If the contents of another section-for instance, section S--are to be dried, a corresponding change in the position of the movable partitions, and in the passages of the hotair iiue, and the doorways, is made.

What I claim as new, and desire to secure by Letters Patent, is- 1. The hot-air ue C, situated beneath or outside of the heating-chamber A, and communicatin g with the same through apertures 0 in the floors of the doorways B, substantially as and for the purpose herein shown and described.

2. The temporary partitions or walls u and doors t, in combination with the heatingchamber A, hot-air flue C, doorways B, and apertures o, substantially as set forth.

In testimony that I claim the foregoing, I have hereunto set my hand this 3d day of November, 1874.

FRED. E. HOFFMANN. v Witnesses:

HELMUTH DUEBERG, MAX BAUMANN. 

